Other Assets (Available-For-Sale Investments) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Other Assets [Abstract]
Available-for-sale equity securities, Cost	$ 31,226	$ 28,265
Available-for-sale equity securities, Gross Unrealized Gains	27,321	1,981
Available-for-sale equity securities, Gross Unrealized Losses		(133)	[1]
Available-for-sale equity securities, Fair Value	$ 58,547	$ 30,113

[1] All unrealized loss positions were held at a loss for less than 12 months.